Sleep disordered breathing in a cohort of children with achondroplasia: correlation between clinical and instrumental findings

BACKGROUND: The aim of the present study was to show the results of an overnight polysomnography in a cohort of 9 children (7 females and 2 males) with achondroplasia, aged between 1 and 12 years (5.56 +/- 4.7 years). All of the children carried the Gly380Arg (G380R) mutation on the FGFR3 gene. METHODS: All the young patients underwent nocturnal polysomnography without sleep deprivation. Sleep staging was noted according to the guidelines of the American Academy of Sleep Medicine. At the time of registration, the parents answered to a Sleep Control Test questionnaire regarding medical history and diurnal and nocturnal symptoms of their children. RESULTS: Respiratory sleep disorder was present in 78% of cases, and was generally mild. In 67% of the children there was respiratory effort for more than 30% of the total sleep time. The sample was divided into two age categories: 5 children under the age of 3 years and 4 children over 10 years old. A higher incidence of sleep disorder was found in the first few years of life, where the obstructive pattern predominates. Regarding sleep architecture, we did not find macroscopic alterations of sleep architecture and its phasic manifestations in our paediatric group. However, parents have not been referred daytime sleepiness, attention deficiency, hyperactivity and nocturnal enuresis. Only one had referred recurrent respiratory infections. CONCLUSIONS: Polysomnography is a very useful tool in the evaluation of sleep-disordered breathing in children with achondroplasia.